Powertrain, generic

P0E3B Hybrid/EV Battery Coolant Pump Overspeed

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0E3B indicates that the electric pump circulating coolant through the high-voltage battery turns faster than commanded. A pump that suddenly spins too freely has usually lost its load, because it is moving air instead of coolant after a leak, a low reservoir or a poorly bled system. No manufacturer documents P0E3B publicly. GM's 2019 hybrid tables (19OBDG01) show how such a check works under a maker-specific code (P19FF): the controller filters the difference between commanded and reported pump speed and flags a deviation in either direction; if the pump is meant to be off but still reports over 250 rpm, that counts as well, all as Type B. The sibling P0E3C covers a pump that is too slow. Battery cooling may be reduced and charge or power limited.

Likely causes

Low coolant level or leak, pump running partly dry
Air left in the battery loop after a repair
Faulty pump electronics or speed feedback signal

Symptoms

  • Hybrid or EV system warning
  • Reduced charging or drive power when the battery warms up

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–900
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

hv battery coolant pump

Related codes

P0E3CP0C4AP0C47U0694

References: gsi.ext.gm.com, law.cornell.edu.